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From Roland Knall via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=8502 

Allow reassembly of sequences when the sequence numbers do not count from 0.

svn path=/trunk/; revision=48548
This commit is contained in:
Evan Huus 2013-03-25 12:53:26 +00:00
parent 7097d6465b
commit 0314bd1c1b
2 changed files with 42 additions and 2 deletions
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33
epan/reassemble.c
View File

@ -641,6 +641,26 @@ fragment_get_reassembled_id(reassembly_table *table, const packet_info *pinfo,
return fd_head;
}
/* To specify the offset for the fragment numbering, the first fragment is added with 0, and
* afterwards this offset is set. All additional calls to off_seq_check will calculate
* the number in sequence in regards to the offset */
void
fragment_add_seq_offset(reassembly_table *table, const packet_info *pinfo, const guint32 id,
const void *data, const guint32 fragment_offset)
{
fragment_data *fd_head;
fd_head = lookup_fd_head(table, pinfo, id, data, NULL);
if (!fd_head)
return;
/* Reseting the offset is not allowed */
if ( fd_head->fragment_nr_offset != 0 )
return;
fd_head->fragment_nr_offset = fragment_offset;
}
/* This function can be used to explicitly set the total length (if known)
* for reassembly of a PDU.
* This is useful for reassembly of PDUs where one may have the total length specified
@ -853,6 +873,7 @@ fragment_add_work(fragment_data *fd_head, tvbuff_t *tvb, const int offset,
fd->flags = 0;
fd->frame = pinfo->fd->num;
fd->offset = frag_offset;
fd->fragment_nr_offset = 0; /* will only be used with sequence */
fd->len = frag_data_len;
fd->data = NULL;
@ -1348,11 +1369,18 @@ fragment_add_seq_work(fragment_data *fd_head, tvbuff_t *tvb, const int offset,
fragment_data *fd_i;
fragment_data *last_fd;
guint32 max, dfpos;
guint32 frag_number_work;
/* Enables the use of fragment sequence numbers, which do not start with 0 */
frag_number_work = frag_number;
if ( fd_head->fragment_nr_offset != 0 )
if ( frag_number_work >= fd_head->fragment_nr_offset )
frag_number_work = frag_number - fd_head->fragment_nr_offset;
/* if the partial reassembly flag has been set, and we are extending
* the pdu, un-reassemble the pdu. This means pointing old fds to malloc'ed data.
*/
if(fd_head->flags & FD_DEFRAGMENTED && frag_number >= fd_head->datalen &&
if(fd_head->flags & FD_DEFRAGMENTED && frag_number_work >= fd_head->datalen &&
fd_head->flags & FD_PARTIAL_REASSEMBLY){
guint32 lastdfpos = 0;
dfpos = 0;
@ -1383,7 +1411,7 @@ fragment_add_seq_work(fragment_data *fd_head, tvbuff_t *tvb, const int offset,
fd->next = NULL;
fd->flags = 0;
fd->frame = pinfo->fd->num;
fd->offset = frag_number;
fd->offset = frag_number_work;
fd->len = frag_data_len;
fd->data = NULL;
@ -1852,6 +1880,7 @@ fragment_start_seq_check(reassembly_table *table, const packet_info *pinfo,
fd_head->next = NULL;
fd_head->datalen = tot_len;
fd_head->offset = 0;
fd_head->fragment_nr_offset = 0;
fd_head->len = 0;
fd_head->flags = FD_BLOCKSEQUENCE|FD_DATALEN_SET;
fd_head->data = NULL;

11
epan/reassemble.h
View File

@ -74,6 +74,9 @@ typedef struct _fragment_data {
guint32 frame;
guint32 offset;
guint32 len;
guint32 fragment_nr_offset; /* offset for frame numbering, for sequences, where the
* provided fragment number of the first fragment does
* not start with 0 */
guint32 datalen; /* Only valid in first item of list and when
* flags&FD_DATALEN_SET is set;
* number of bytes or (if flags&FD_BLOCKSEQUENCE set)
@ -264,6 +267,14 @@ fragment_start_seq_check(reassembly_table *table, const packet_info *pinfo,
WS_DLL_PUBLIC fragment_data *
fragment_end_seq_next(reassembly_table *table, const packet_info *pinfo,
const guint32 id, const void *data);
/* To specify the offset for the fragment numbering, the first fragment is added with 0, and
* afterwards this offset is set. All additional calls to off_seq_check will calculate
* the number in sequence in regards to the offset */
WS_DLL_PUBLIC void
fragment_add_seq_offset(reassembly_table *table, const packet_info *pinfo, const guint32 id,
const void *data, const guint32 fragment_offset);
/* to specify how much to reassemble, for fragmentation where last fragment can not be
* identified by flags or such.
* note that for FD_BLOCKSEQUENCE tot_len is the index for the tail fragment.